Photocontrol device with a surge protection function

ABSTRACT

This disclosure discloses a photocontrol device with a surge protecting function, including: a photocontrol unit, a surge protection unit, and a device base. The photocontrol unit includes a plug; the device base includes a socket corresponding to the plug; the photocontrol unit is connected to the surge protection unit to form a whole body, which is connected to the device base. The surge protection unit is connected in parallel to a phase line terminal and a neutral line terminal of the photocontrol unit, a ground line terminal of the surge protection unit is connected to a conductive part on the device base by at least a ground connector, and the conductive part is connected to ground. The ground line terminal can be attached on the outer surface of the surge protection unit, and also can be connected to the device base via a ground connector.

CROSS REFERENCE

This application is a continuation in part application of U.S. Ser. No. 15/117,456 filed on Aug. 9, 2016, which is a national phase application of PCT/CN2015/072238 filed on Feb. 4, 2015, which claims priority to a Chinese application CN201420150952.7 filed on Mar. 31, 2014, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to a photocontrol device, more particularly, to a photocontrol device with a surge protecting functionality.

BACKGROUND

In recent years, with the rapid development of global economy, there is a significant increase in energy demand, causing an increasingly prominent contradiction between energy supply and demand. Therefore, energy saving is becoming more and more important. Nowadays, domestic control and operating methods of road lighting are the dedicated control line, the control line with a load, the timing control and other control methods. However, most of the traditional control methods of road lighting focus on control or timing control. This results in loss of energy. Photo control is a well-known method used for energy saving. The principle of photo control is that, based on changes of the photosensitive component with respect to changes of the intensity of the light source, the on/off of the lighting power supply is controlled, so as to achieve the most efficient energy control of the lighting power supply. Also, the photocontrol device is mounted outside the road lamp, using a quick plug installation, which enables the operation without cutting off the electricity. It only needs one person to install or replace, and only a few minutes to complete, lowering the maintenance costs greatly.

With LED (Light-Emitting Diode) road lighting being widely used, the photocontrol device and LED lighting are the two engines of the road lighting system for saving energy and reducing energy consumption. The photocontrol device is on the top end of the lighting, and on the front end of a driving power, which has the characteristic of easy and quick replacement. Since the LED road lighting and the photocontrol device are particularly sensitive to overvoltage and surge current, without reliable protection measures, an entire road lighting system can be paralyzed by the thunderstorm or thunder overvoltage, which brings significant economic losses and potential safety risk. Thus, a surge protection device has become a necessary device for the photocontrol device, LED driving device, and LED Light anti-surge.

When the surge protection device performs the security responsibilities to protect the photocontrol device, LED driving device, and LED light, under a long-time surge attacks, it is likely to be damaged and needs to be replaced frequently. At present, roost of the surge protection device of the LED road lighting is mounted inside the lamp, while the LED road lighting is usually mounted on the upper end of the light pole which has a height of 5-10 m. Therefore, the installation and replacement of the surge protection unit require the use of lift trucks to perform elevated work. Moreover, the replacement of the surge protection device can only be performed in a power-off status, which may take as long as one hour. Thus, the cost of installation and maintenance is high, and operational safety of staff responsible for installation and maintenance is a concern.

SUMMARY OF THE INVENTION

One of the purposes of the application is to solve problems faced by the prior art by providing a device combining the photocontrol device with the surge protection device, allowing management of lighting energy consumption and also thunder and surge protection function. At the same time, the difficulty of the high cost of installation and maintenance of the surge protection device is solved, contributing to the energy saving and reducing consumption of photo control lighting, and improving the lifetime and safety of the lighting system. In particular, the complexity and danger of security maintenance are greatly reduced, thereby improving the safety of maintenance staff.

The application provides a photocontrol device with photocontrol and surge protection functions. In one implementation, a photocontrol device includes a photocontrol unit, a surge protection unit, and a device base. The photocontrol unit includes a shell, a photocontrol circuit, a bottom cap, and a plug. The shell is disposed over the bottom cap. The photocontrol circuit is disposed between the shell and the bottom cap. The first plug is mounted below the bottom cap. The output terminal of the photocontrol circuit is electrically connected to the first plug. The surge protection includes a hermetic chamber. A surge protection circuit is disposed inside the hermetic chamber. The surge protection circuit includes at least one protection component. The surge protection unit is designed as differential mode, common mode, or all-mode scheme according to the different number of protection components.

There are four methods to manufacture each protection component, namely, using the varistor alone; using a current fuse and a varistor in series; using a thermal protection device and a varistor in series; and using a current fuse, a thermal protection device, and a varistor in series. The security of the four methods progressively increases from low, fair, good, to excellent. This application preferentially uses the third method to manufacture the surge protection component. If necessary, common mode surge protection component is connected to a gas discharge tube in series, isolating the leakage current to the ground. The device base is provided with the socket corresponding to the plug. The surge protection unit is connected in parallel to a power supply phase line (Lin) terminal and neutral line (N) terminal of the photocontrol unit. The ground line (PE) terminal of the surge protection unit is connected to a conductive part on the device base by at least a ground connector, and the conductive part is connected to the ground.

As a preferable solution, the ground connector includes a lock cover, an elastic member, and a ground connector push rod. A conductive part in the device base is a mounting screw. The push rod of the ground connector is connected to the head of the mounting nut in a contact manner. When the plug of the photocontrol unit connects to the socket of the photocontrol device, the push rod of the ground connector can have a good electrical contact with the mounting nut by the elastic force of the elastic member. Thus, the mounting nut which fixes the photocontrol device socket shell is used to connect to the ground line in a pressing manner, so as to connect to the ground to form a surge current discharge path.

In one embodiment, a built-in type structure is disclosed, wherein the surge protection unit is integrated into the photocontrol unit, forming a whole. When being mounted, only the plug of the photocontrol unit is needed to insert into the socket of the device base. In such built-in type structure, the surge protection unit is added into the existing photocontrol unit. Therefore, the internal photocontrol unit can be divided into two regions. One region is used to provide the surge protection component designed for differential mode and common mode or all-mode scheme of the surge protection unit. The other region is used to provide photocontrol circuit with function of the conventional photocontrol device. Specifically, the surge protection unit is provided on PCB (Printed Circuit Board) plate with the photocontrol circuit of the photocontrol unit, sharing the PCB plate with the photocontrol unit. In addition, a ground connector with elasticity is provided on the bottom cap of the photocontrol unit. The location and number of the ground connector correspond to that of the mounting screw which fixes the shell of the device base. When the plug of the photocontrol unit is inserted into the device base completely, the elastic force is used to form a good electrical contact with, the mounting screw. Inside the photocontrol device, the ground connector is connected to the (PE) terminal of surge protection unit to term a surge current discharge path to the ground.

In another embodiment, a transfer type of structure is disclosed. Under the condition that no change is made to the photocontrol unit and the internal structure of the photocontrol device socket, the surge protection unit is manufactured as an independent entity, and is provided between the photocontrol unit and the device base. The independent integrated surge protection unit connects to the photocontrol unit by a connector provided thereon to form a whole. The connector includes a female socket terminal and a male socket terminal. When being installed, the plug of the photocontrol unit is inserted into the female socket terminal of the connector of the surge protection unit and the male socket terminal of the connector of the surge protection unit is inserted into the socket of the device base, providing the connector makes the independent integrated surge protection unit have a transfer function. Therefore, the photocontrol unit and the independent integrated surge protection unit are successfully separated in structure, but combined in function. In such a transfer structure, in order to make the independent integrated surge protection unit work properly, a ground connector may be provided to connect to the (PE) terminal of the independent integral surge protection unit to form a surge current discharge path to the ground. Such manner has an advantage of an integrated solution. The independent integrated surge protection unit and the photocontrol unit can be replaced separately and quickly. Thus, the cost of post-maintenance and replacement of device is greatly reduced.

In addition, in the transfer structure of the application, the independent integrated surge protection unit is of a pie-like structure, which includes an upper cover, a lower cover, and a hermetic chamber between the upper and lower covers. The upper cover and lower cover are fixedly connected to form a whole. There are through holes provided on the upper cover for the plug of the photocontrol unit. The connection between the upper and lower covers can be achieved by any manner known by persons skilled in the art, including but not limited to: detachable manners such as projection, grooves provided on the upper and lower covers, or internal, external threads and etc., or non-detachable manners such as bonding, riveting, welding and etc.

Preferably, the connection between the upper and lower covers is achieved by screws and nuts. Specifically, upper center holes are arranged on the upper cover, and lower center holes are arranged on the lower cover. The screw passes through the center hole on the upper cover and the center hole on the lower cover in turn. A water-proof pad is arranged on the bottom of the lower cover, together with a nut for fastening.

Preferably, the surge protection unit includes at least one protection component. Bach protection component includes a varistor and at least one thermal protection device that are connected to each other in series. In all-mode protection, a gas discharge tube can be connected to varistor in series, isolating leakage current to the ground.

The thermal protection device can be a mechanical thermal desorption device, thermal fuse, low-melting point alloy disconnect device, bimetal thermal circuit breaker, current fuse, or a combination in series of any number of the above. The thermal protection is achieved by using the over thermal protection feature of the thermal fuse. One embodiment uses “a varistor provided with the alloy type of thermal fuse.”

In another embodiment, the ground connector includes a first lock member, a second lock member and an elastic member, which are connected sequentially; wherein the conductive part is disposed in the middle of the device base; and wherein the elastic member contacts the conductive part. The conductive part may be a screw.

In another embodiment, a photocontrol device with a surge protecting function is provided, including: a photocontrol unit, a surge protection unit, and a device base; wherein the photocontrol unit includes a plug; the device base includes a socket corresponding to the plug; wherein the photocontrol unit is connected to the surge protection unit to form a whole body, and the whole body is connected to the device base; wherein the surge protection unit is connected in parallel to a phase line terminal and a neutral line terminal of the photocontrol unit, and a ground line terminal of the surge protection unit is attached to an outer surface of the surge protection unit.

In another embodiment, a device base incorporating a surge protection unit is provided. A surge protection unit, especially a surge protection unit with a thermal protection function is included in the device base, and thus the control device base can be used for both connection and surge protection.

The device base further includes the following features. The device base further comprises an electrical connection unit group, the electrical connection unit group includes a first electrical connection unit, adapted to be connected between a neutral line of a photocontrol device and an external circuit a second electrical connection unit, adapted to be connected between a switch of the photocontrol device and the external circuit, wherein the surge protection unit is located between the first electrical connection unit and the second electrical connection unit. The device base further comprises a ground connection wire, wherein the device base includes a first surge protection unit, a second surge protection unit and a third surge protection unit, the first surge protection unit is connected between the first electrical connection unit and the second electrical connection unit, the second surge protection unit is connected between the first surge protection unit and the ground connection wire, and the third surge protection unit is connected between the second electrical connection unit and the ground connection wire. The first surge protection unit is a first varistor, the second surge protection unit is a second varistor and a first thermal fuse connected in series, and the third surge protection unit is a third varistor and a second thermal fuse connected in series. Alternatively, the surge protection unit is a varistor. Alternatively, the surge protection unit is a varistor and a thermal fuse connected in series. The second electrical connection unit is connected to a third thermal fuse in series. The device base farther comprises a failure indication component adapted to indicate whether a thermal fuse in the surge protection unit fuses off, wherein the failure indication component is connected to the at least one surge protection unit.

One of the benefits of the invention is that by providing integrated or transfer type surge protection unit, the photocontrol device with photo lighting control has the protection function of surge voltage and surge current at the same time. The elastic ground connector is connected to the mounting screw on the socket of the device base in a contact way, to form a surge current discharge path to the ground. Providing the plug-in connector achieves an easy installation and replacement of the surge protection unit, as well as separate replacement of the surge protection unit and the photocontrol unit. At the same time, the problem of the difficulty of the installation of the surge protection and high maintenance cost is solved. Thus, the contribution is made to the energy saving and consumption reducing of the photo control lighting, and the lifetime and safety of lighting system are improved. In particular, the complexity and danger of security maintenance are greatly reduced, thus improving the safety of maintenance staff. Different connection modes of the circuit inside the surge protection unit, realizes the protection requirements of common mode, differential mode, and all-mode of the LED lighting power supply system.

Additionally, the surge protection unit is included in the device base, which already has means for grounding. Hence, the surge protection unit doesn't need to be adapted for grounding.

One mode the surge protection unit can be built into compact-sized electronic device or in the transfer mode the surge protection unit can be quickly replaced. The invention is not limited to be used in LED street lights and photocontrol device products, it can also be used in other compact electrical and electronic equipment, such as a sound controller, a monitor, and so on.

The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will become apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the following drawings, further descriptions are made to the application, wherein:

FIG. 1A is a built-in type functional block diagram of the photocontrol device with a surge protecting function in the first embodiment.

FIG. 1B is a pie-transfer type functional block diagram of the photocontrol device with a surge protecting function in the second embodiment.

FIG. 2A is a schematic diagram of the appearance of the first, embodiment of the application.

FIG. 2B is a schematic diagram of the structure of the first embodiment of the application.

FIG. 2C and FIG. 2D are all-mode protection circuit diagrams of the surge protection unit of the embodiment of the application.

FIG. 2E is a schematic diagram of the structure of the surge protection unit of the first embodiment of the application.

FIG. 3 is a schematic diagram of the structure of the ground connector of the application.

FIG. 4A is a schematic diagram of the appearance of the second embodiment of the application.

FIG. 4B is a top view of the second embodiment of the application.

FIG. 5 is an internal structural diagram of the surge protection unit of the second embodiment of the application.

FIG. 6 is a schematic diagram of physical connections of the surge protection unit of the second embodiment of the application.

FIG. 7A is a perspective view of the photocontrol device having a surge protection unit according to the first embodiment, wherein the surge protection unit is connected to the ground via another ground connector and the surge protection unit is integrated with the photocontrol unit.

FIG. 7B is a perspective view of the photocontrol device having a surge protection unit according to the second embodiment, wherein the surge protection unit is connected to the ground via another ground connector and the surge protection unit is separate from the photocontrol unit.

FIG. 8 is a schematic diagram of the ground connector in FIG. 7A and FIG. 7B.

FIG. 9A is a perspective view of the photocontrol device having a surge protection unit according to the first embodiment, wherein the outer surface of the surge protection unit is connected to the ground and the surge protection unit is integrated with the photocontrol unit.

FIG. 9B is a perspective view of the photocontrol device having a surge protection unit according to the second embodiment, wherein the outer surface of the surge protection unit is connected to the ground and the surge protection unit is separate from the photocontrol unit.

FIG. 10 is a perspective view of a device base having a surge protection unit according to the third embodiment.

FIG. 11 is a first circuit schematic diagram of a device base as shown in FIG. 10.

FIG. 12 is a second circuit schematic diagram of a device base as shown in FIG. 10.

FIG. 13 is a first explosive view of a device base according to FIG. 11.

FIG. 14 is a second explosive view of a device base according to FIG. 12.

FIG. 15 is a circuit schematic diagram of the surge protection unit included in device base as shown in FIG. 10.

FIG. 16 is a perspective view of the surge protection unit included in device base as shown in FIG. 10.

FIG. 17 is a perspective view of a gas discharge tube component included in device base as shown in FIG. 10.

FIG. 18 is a perspective view of an electrical connecting unit included in the device base as shown in FIG. 10.

FIG. 19 is a perspective view illustrating how a transition electrode is connected in the device base as shown in FIG. 14.

FIG. 20 is a perspective view illustrating how the surge protection unit is connected in the device base as shown in FIG. 13.

FIG. 21 is a perspective view illustrating how the surge protection unit is connected in the device base as shown in FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the application will be described more completely by embodiments accompanied by the drawings, wherein only a few embodiments have been shown. However, in practice, the application can be embodied in many different forms, and should not be limited to the embodiments in the text. These embodiments are provided for the purpose of better understanding of the application.

FIG. 1A and FIG. 1B are functional block diagrams of the device with photocontrol device and a surge protecting function in the first embodiment and the second embodiment respectively. It can be used in LED road lighting power. As shown in FIG. 1A and FIG. 1B, the photocontrol device of the application includes photocontrol unit 1, surge protection unit 2A, 2B, and device base 3. The surge protection unit 2A, 2B are connected in parallel to the power supply phase line (Lin) and the neutral line (N) of photocontrol unit 1. The ground line (PE) terminal of surge protection unit 2A, 2B is connected to the conductive part on device base 3 by ground connector 4. The conductive part is connected to the ground by wires. Therefore, the photocontrol device with a surge protection function is formed.

FIG. 2C and FIG. 2D are circuit diagrams of surge protection units 2A and 2B of the embodiment of the application, and the circuit diagrams in FIG. 2C and FIG. 2D can be used both in surge protection units 2A and 2B of the embodiment of the application. As shown in FIG. 2C, the working current of LED street light and photocontrol unit 1 does not go through the thermal protection disconnecting device which between L-N differential mode protection in the surge protection component. The thermal protection disconnecting device is the thermal fuse which between L-N differential mode protection, but the LED streetlights still work even the fuse is disconnected. As shown in FIG. 2D, the working current of LED street lights and photocontrol unit 1 goes through thermal protection disconnecting device of the surge protection component which is between L-N differential mode protection. The thermal protection disconnecting device is the thermal fuse which between L-N differential mode protection. When the thermal fuse disconnects, the LED street light is powered off and stops working.

The First Embodiment

FIG. 2A and FIG. 2B are schematic diagrams of the appearance and the structure of the photocontrol device with a surge protecting function in the first embodiment of the application. As shown in the figures, photocontrol unit 1, surge protection unit 2A which is built in photocontrol unit 1, and device base 3 are shown from top to bottom in turn. Surge protection unit 2A is integrated into photocontrol unit 1, being used together with device base 3, to form a photocontrol device with a surge protection function, in the embodiment, existing standard photocontrol unit 1 and existing standard device base 3 are used, both of which are connected to each other through a socket and a plug, so as to achieve versatility.

Photocontrol unit 1 includes shell 101, PCB plate with photocontrol circuit 102, three sets of electrical connectors 103, bottom cap 104, and plug 105. Details are shown as below: shell 101 is disposed over bottom cap 104. An accommodating space is formed between shell 101 and bottom cap 104, PCB plate with photocontrol circuit 102 is provided in the accommodating space. This PCB plate 102 contains not only the circuit which can achieve photo control function, but also preserves space for surge protection unit 2A. Three sets of electrical connectors 103 are disposed on bottom cap 104. Standard plug 105, which is the first plug, is installed under bottom cap 104. Preferably, first plug 105 is three pieces of metal. The output terminal of PCB plate with photocontrol circuit 102 is connected to the three pieces of metal of plug 105 by three sets of electrical connectors 103 respectively.

As shown in FIG. 2B, surge protection unit 2A is further disposed inside the accommodating space which is between shell 101 and bottom cap 104 of photocontrol unit 1, more specifically, on PCB plate with photocontrol circuit 102. The phrase line (Lin, Lout) terminal and the neutral line (N) terminal of surge protection unit 2A are connected in parallel to the input terminal of photocontrol unit 1 by printed circuit board (PCB). In the first embodiment, as shown in FIG. 2E, surge protection unit 2A includes cylindrical shell 201A, PCB plate with the photocontrol circuit 102 used together with the photocontrol circuit; and a hermetic chamber formed by cylindrical shell and PCB plate 102. The cylindrical shell is made of engineering plastics which has a flame retardant grade in line with UL94V0 level. The surge protection components inside surge protection unit 2A are electrically insulated from the electric parts on photocontrol unit 1, so as to reduce the volume of the product. Meanwhile, the hermetic chamber is filled with insulating potting material which has a flame retardant grade in line with UL94V0 level and has a high thermal resistance. Therefore, this surge protection unit 2A can entirely join in photocontrol unit 1 for long-term use.

In the first embodiment, the surge protection circuit of the surge protection unit can be formed with the differential mode alone, the common mode alone, or the all-mode protection manner which has differential mode and common mode simultaneously, as necessary. Typical design of the embodiment can use all-mode protection, which includes three protection components. Each protection component includes a varistor and a thermal protection device that are connected in series. The thermal protection device can be a thermal fuse. A gas discharge tube can be connected in series with the varistor in the common model protection if necessary and is used to insulate the leakage current to the ground in normal operation. In the embodiment, the thermal protection device can cut off the circuit in time when the varistor degrades to failure or undertakes a temporal overvoltage, avoiding a fire in the varistor. The thermal fuse shows one of the many implementations known to the persons skilled in the art, which includes but is not limited to the mechanical tripping manner, the thermal fuse, the low-melting-point alloy or the bimetallic circuit breaker, etc.

In the surge protection unit of the first embodiment, the thermal protection device provided is used as a fail-safe for the varistor protection device, which is implemented using the technology of “a varistor provided with the alloy type of thermal fuse”. More specifically, electrodes 205A, 206A, and 207A are welded on the surface of the three varistors 204A. Three thermal fuses 201A are connected to three varistors 204A by electrodes 205A, 206A, and 207A through the shortest thermal conductive path effect, forming electrical series respectively, to become the surge protection components. The leads of the three surge protection components are welded on PCB plate 102. Gas discharge tube 214A is connected in series to the surge protection component with common mode protection.

Device base 3 includes a cylindrical body. Three grooves/holes are arranged in the middle of the body. Three grooves/holes form socket 301 on device base 3, and are used to match and connect to plug 105 of photocontrol unit 1. At least one hole 304 is provided on the edge of the body along its circumferential direction, and is used for mounting screw 302 to pass through and fasten tightly with mounting nut 303. Mounting screw 302 is used for fixing the device base, and meanwhile, is connected to the ground by wire. The head of mounting screw 302 can be made into a shape of an electrically contact to form a ground conductor, and form a good electrical connection with ground connector 4. The edge of the head is provided with corners that can form tightened torques. In the embodiment, the number of mounting screw 302 can be set to one or more as necessary. Preferably, two mounting screws 302 are provided symmetrically, but not limited to this.

In the embodiment, when surge protection unit 2A is entirely integrated into photocontrol unit 1, since except for power supply phase line (Lin, Lout) terminal and neutral line (N) terminal, surge protection unit 2A needs to be provided with the ground line (PE) terminal, thus, at least one elastic ground connector 4 is provided on bottom cap 104 of photocontrol unit 1, so as to connect to the ground line (PE) of surge protection unit 2A. The position and number of ground connectors 4 should correspond to those of mounting screws 302. The number of the ground connectors can be set according to actual needs, such as one or more. In the preferred embodiment, two mounting screws 302 are provided symmetrically, but not limited to this.

The specific structure of ground connector 4, referring to FIG. 3, includes to ground connector lock cover 401, elastic, member 402, ground connector push rod 403 in sequentially contacting connection. In the application, elastic member 402 can be any spring which may be used in the art, such as tension springs, compression springs, torsion springs, bending springs, and etc., and also can be elements that are made of other elastic materials. Three parts of ground connector 4, ground connector push rod 403, elastic member 402, and ground connector lock cover 401 are enclosed in corresponding mounting through holes 106 on bottom cap 104 in order.

In use, plug 105 of photocontrol unit 1 with surge protection unit 2A is aligned with the socket 301 of device base 3, and is pressed down so that plug 105 is inserted into socket 301 normally, such that the photocontrol circuit 102 in photocontrol unit 1 is on, and thus encompasses the photo control function in a conventional sense. Once plug 105 is installed, at the same time, the end of ground connector push rod 403 of ground connector 4 forms a good electrical connection to the head of mounting screw 302 of device base 3 by the elastic force of spring. Therefore, the ground line (PE) terminal of surge protection unit 2A is connected with the ground by ground connector 4 and mounting screw 302. When the surge occurs, the surge will be conducted into the ground by the wire connecting to mounting screws 302, so as to form the surge protection, having the surge protection function.

In the first embodiment without, changing traditional photocontrol device function, the surge protection unit is added to the standard photocontrol unit, and ground connector is also added to achieve the connection between the ground line (PE) terminal of the surge protection unit and the ground, forming a surge current discharge path to the ground, creating the photocontrol device with the full-mode surge protection function described in the application. Since the surge protection unit is entirely integrated into the photocontrol unit, functions of both are combined, but the installation method of the photocontrol device is not changed. Therefore, the photocontrol device with a surge protection function in the application can be the same as an ordinary photocontrol device, that is, can be directly installed outside the lamp using a quick plug-in installation manner. As such, it does not need to cut off the power supply when replacing. Only one person is needed to operate. The time and labor are saved. Especially, in high labor cost countries like Europe and America, the post-maintenance cost is greatly reduced, and the operational safety of the staff is improved.

The Second Embodiment

Since surge protection unit 2A is entirely integrated into photocontrol unit 1 in the first embodiment, the entire assembly must be replaced when any part of the photocontrol device or the surge protection unit is damaged. If only the surge protection unit needs to be replaced because of deterioration caused by continuous attacks of the surge or damage caused by temporary overvoltage, there is no need to replace the photocontrol device together at this time, so as to reduce waste. To solve these problems, the application also provides a second type of embodiment.

FIG. 4A and FIG. 4B show the appearance schematic diagram and the top view of the photocontrol device with surge protection in the second embodiment. As shown in the figures, photocontrol unit 1, surge protection unit 2B, and device base 3 are shown from top to bottom in turn. The internal structure and function of photocontrol unit 1 and device base 3 are the same as those described in the first embodiment. However, in the second embodiment, surge protection unit 2B is not integrated into photocontrol unit 1, but is connected to photocontrol unit 1 and device base 3 respectively by a connector which is provided on the surge protection unit. These three parts form a three-layer laminated structure by the combination of plug and socket. Photocontrol unit 1 and base 3 can use the standard photocontrol device assemblies commonly used in the art.

FIG. 5 shows the internal structure of the surge protection unit 2B in second embodiment. As shown in FIG. 5, surge protection unit 2B includes upper cover 201B, lower cover 202, and surge protection component disposed inside the hermetic space which is between upper cover 201B and lower cover 202. In order to ensure insulation requirements, upper cover 201B and lower cover 202 can be made of engineering plastics material which meets the flame retardant grade in line with UL94V0 level. Insulation potting material which meets the flame retardant grade in line with UL94V0 level and has a high thermal resistance can also be used to fill between the upper cover and the lower cover, so as to achieve an insulating effect. In use, upper cover 201B and lower cover 202 match and are fixed to form a whole. As shown in the figure, the shape of the whole is a pie, but not limited to this. It can be formed into any shape as necessary. Furthermore, upper cover 201B and lower cover 202 can be fixedly connected using any manner known by persons skilled in the. For example, detachable manners such as projection, groove, internal or external thread, and etc. can be provided on the upper cover and the lower cover to form the connection. Otherwise, non-detachable manner such ad bonding, riveting, welding, and etc., can be used to form the connection, but not limited to this.

In the second embodiment, upper cover 201B and lower cover 202 are connected by means of screws and nuts. Specifically, center holes 221, 222 are arranged in the central region of the upper cover 201B and lower cover 202. The screw 217 passes through center hole 221 of the upper cover and center hole 222 of the lower center, with nut 218 being used at the bottom of lower cover 202 for fastening. Furthermore, waterproof pad 216 can also be provided for further sealing. Three through holes 220 are further provided inside upper cover 201B. The sector regions shown in FIG. 5 are through holes 220. The three through holes correspond to three metal pieces on plug 105 of photocontrol unit 1, such that plug 105 can be inserted into socket 220 to connect to the connector of surge protection unit 2B. Three electrical connectors 208, 211, 215 are provided inside lower cover 202, including connector for incoming line terminal (Lin) 208, connector of load terminal (Lout) 211 and connector of neutral line terminal (N) 215. The structures of the three electrical connectors 208, 211, 215 are similar, and their shapes are basically the same. However, in order to prevent L, N terminals misconnection, the plug size of one of the connectors (such as N-terminal) can be set slightly larger. For example, the electrical connector for incoming line terminal “Lin” 208, as shown in FIG. 5, one terminal of the connector for incoming line terminal “Lin” 208 is a female socket 208A which is made by bending an elastic metal sheet. This female socket 208A correspondingly receives plug 105 which inserts from through hole 220, so as to achieve the connection between photocontrol unit 1 and surge protection unit 2. While another opposite terminal of electrical connector 208 is male plug 208B which extends downwards from lower cover 202. This male plug 208B is exactly the same as plug 105, and is used to insert into socket 301 of device base 3, so as to achieve the connection between surge protection unit 2B and device base 3. Furthermore, the female socket 208A and male plug 208B are joined by welding or riveting, or can be formed integrally if necessary.

The second embodiment is also provided with two symmetrical elastic ground connectors 4 for connecting the ground line (PE) terminal of surge protection unit 2B. The structure and number of ground connectors 4 are the same as in those in the first embodiment, referring to FIG. 3. In the second embodiment, the differences from the first embodiment are that ground connector push rod 403, elastic member 402, ground connector lock cover 401 are enclosed sequentially into respective mounting through holes 219 that are located lower cover 202, as shown in FIG. 5.

In the second embodiment, the surge protection circuit also includes three surge protection components. Each surge protection component includes a varistor and a thermal protection device that are connected in series. The surge protection component can be formed with the differential mode alone, the common mode alone, or the all-mode manner which has the differential mode and the common mode simultaneously, as necessary. A gas discharge tube can be connected in series with the varistor in the common model protection as necessary, and used to insulate the leakage current to the ground in normal operation. In the embodiment, the thermal protection device is thermal protection disconnecting device, i.e., thermal fuse 210B. The thermal protection disconnecting device can also be implemented by any manner known by person skilled person in the art, including but not limited to: mechanical tripping, thermal fuse, low-melting-point alloy or bimetallic circuit breaker, etc. The thermal protection device is a mechanical thermal desorption device, thermal fuse, low-melting point alloy disconnect device, bimetal thermal circuit breaker or current fuse, or a combination in series of any number of the above.

FIG. 6 shows a physical connection diagram of surge protection unit 2B in FIG. 5 in detail. As shown, in FIG. 6, three surge protection components and discharge tubes are placed in the hermetic space between upper cover 201B and lower cover 202 in a tiled manner. The surge protect circuit includes first electrode 203, three varistors 204B, second electrode 205B, third electrode 206B, fourth electrode 207B, three thermal protection disconnecting device i.e., thermal fuse 210B, input electrode connecting line of discharge tube 212B, output terminal connecting line of discharge tube 213B, and discharge tube 214B. Three varistors 204B are respectively welded between first electrode 203B and second electrode 205B, between second electrode 205B and third electrode 206B, between fourth electrode 207B and third electrode 206B. Three thermal protection disconnecting devices, i.e., thermal fuses 210B are respectively provided on first electrode 203B, third electrode 206B, and fourth electrode 207B. One terminal of each thermal protection disconnecting device (i.e., thermal fuse 210B) is electrically connected to its corresponding electrode. Second electrode 205B is electrically connected to connector 215 of neutral line terminal “N”. The other terminal of the thermal protection disconnecting device (i.e., thermal fuse 210B) protection device on the third electrode 206B is electrically connected to connector of incoming line terminal ‘Lin’ 208. Input electrode connecting line of discharge tube 212B is electrically connected to the other terminal of thermal protection disconnecting device (i.e., thermal fuse 210B) on first electrode 203B, the other terminal of thermal protection disconnecting device (i.e., thermal fuse 210) protection device on fourth electrode 207B, and one terminal of discharge tube 214B respectively. Output electrode connecting line of discharge tube 213B is electrically connected to the other terminal of the discharge tube 214B and ground connector push rod 403.

In use, plug 105 of photocontrol unit 1 is aligned with three through holes 220 on upper cover 201B of surge protection unit 2B, and is pressed down, so that plug 105 passes through holes 220, and inserts into female socket terminals such as 208A of three electrical connectors 208, 211, 215 respectively, to form a good connection. After plug 105 of photocontrol unit 1 is installed, male plug terminal (such as 208B) of connector 208, 211, and 215, which extends under lower cover 202 of surge protection unit 2B is aligned with socket 301 of device base 3, and is pressed down, so that male plug is connected normally to socket 301, such that the photocontrol circuit 102 in photocontrol unit 1 is on, and thus has the photocontrol device function in conventional sense. At the same time, the end of push rod 403 of ground connector 4 contacts the head of mounting screw 302 on device base 3 by the elastic force of elastic member 402, to form a good electrical connection. Thus, the ground line (PE) terminal of surge protection unit 2B conducts to ground through ground connector 4 and mounting screw 302. When the surge occurs, it will be conducted into the ground by the wire connected to mounting screws 302, to form the function of full-mode surge protection device.

The second embodiment does not change the function of the traditional photocontrol device, and does not make any change to the structure of the photocontrol device either. It is only required to ensure the locking screw on the photocontrol device has good conductive properties and connects to the ground. The surge protection unit is added between the existing photocontrol unit and the device base. Also, through plug-in electrical connectors provided on the surge protection unit, and ground connectors, the surge protection function is achieved, thus facilitating easy installation and flexible replacement of the photocontrol device and the surge protection unit. In addition to the advantages of quick plug-in and direct installation it also provides an advantage that the photocontrol unit and the surge protection unit can be replaced separately. Through different electrical connections inside the surge protection unit, protection requirements of the common mode, the differential mode, and the all-mode in the LED lighting power supply system are achieved.

Referring to FIG. 7A, the ground line (PE) terminal of surge protection unit 2A in the first embodiment is connected to the ground via another ground connector 6. There may be screw 5 disposed in the middle of device base 3 and screw 5 contacts ground connector 6 at the bottom of surge protection unit 2A.

Similarly, referring to FIG. 7B, the separate surge protection unit 2B in the second embodiment may further include ground connector 6 at the bottom of surge protection unit 2B. There may be screw 5 disposed in the middle of device base 3 and screw 5 contacts ground connector 6.

Referring to FIG. 8, ground connector 6 may further include first lock member 601, second lock member 602 and elastic member 603. First lock member 601 may be connected to ground line FE terminal of the surge protection unit 2A, 2B. First Sock member 601 may be a metal sheet. First lock member 601 may be connected to second lock member 602, which may further be connected to elastic member 603. Elastic member 603 contacts screw 5, which may be connected to the ground. Hence, ground line PE terminal of the surge protection unit 2A, 2B may be connected to the ground via the contact of screw 5 and ground connector 6.

Referring to FIG. 9A, the ground line (PE) terminal of surge protection unit 2A in the second embodiment may be attached to the outer surface of surge protection unit 2A and may be connected to the ground.

Similarly, referring to FIG. 9B, the separate surge protection unit 2B in the second embodiment may include a ground line attached to the outer surface of surge protection unit 2B and may be connected to the ground.

The Third Embodiment

The surge protection unit may also be incorporated into the device base, which already has means for grounding. Hence, the surge protection unit doesn't need to be adapted for grounding.

The First Implementation

As shown in FIGS. 10, 11 and 13, device base 1 with surge protection function includes shell 2, surge protection unit group 3, electrical connection unit group 4, base 5, failure indication component 6, gas discharge tube component 7, ground connection wire 11. Electrical connection unit group 4 includes first electrical connection unit 4 a, second electrical connection unit 4 b and third electrical connection unit 4 c. First electrical connection unit 4 a is used to connect a neutral line of the photocontrol device and a neutral line of a low voltage distribution system, i.e., N-N′ are connected. Second electrical connection unit 4 b is used to connect a switch of the photocontrol device and a phase line of low voltage distribution system, i.e., Li-Li′ are connected. Third electrical connection unit 4 c is used to connect the switch of the photocontrol device and a phase line of an illuminating device, i.e., L0-L0′ are connected. As illustrated in FIG. 9, first electrical connection unit 4 a, second electrical connection unit 4 b and third electrical connection unit 4 c are all composed of plug-sleeve part 401 and insulated conductive wire 402. Plug-sleeve part 401 is made of elastic metal and is processed by deactivators and preservatives. A plurality of holes is punched in plug-sleeve part 401 for fixing or connecting the conductors. The insulation layer is removed from insulated conductive wire 402 and an end of insulated conductive wire 402 is then inserted into plug-sleeve part 401 from bottom to top and connected to plug-sleeve part 401 by soldering or pressure welding.

Surge protection unit group 3 may be connected between first electrical connection unit 4 a and second electrical connection unit 4 b. Surge protection unit group 3 may include first surge protection unit 3 a, second surge protection unit 3 b and third surge protection unit 3 c. The three surge protection units may be all thermal protection varistors, each of which is composed of a varistor and a thermal fuse connected in series. First surge protection unit 3 a may be connected between first electrical connection unit 4 a and second electrical connection unit 4 b. Second surge protection unit 3 b may be connected between first electrical connection unit 4 a and ground connection wire 11. Third surge protection unit 3 c may be connected between second electrical connection unit 4 b and ground connection wire 11.

Device base 1 may also include gas discharge tube component 7, one end of which may be connected to second surge protection unit 3 b and third surge protection unit 3 c and the other end of gas discharge tube component 7 may be connected to ground connection wire 11. As shown in FIG. 17, gas discharge tube component 7 may include gas discharge tube 701 and connecting electrode 702. Connecting electrode 702 may be electrically connected to gas discharge tube 701. Three connecting terminals may extend from connecting electrode 702 and each connecting terminal has a hole therein.

Device base 1 may further include failure indication component 6, connected to leading out terminal 12 of each surge protection unit as shown in FIGS. 15 and 16. Failure indication component 6 may be used to indicate whether the thermal fuse in the surge protection unit fuses off. Failure indication component 6 may be installed between shell 2 and base 5 and closed to the wall of shell 2. The light of failure indication may be seen from the outside of shell 2. There may be a circular hole and a transparent cover 601 is covered on the circular hole. Seal 602 may be provided between cover 601 and shell 2 for sealing function.

Device base 1 may further include signal transmission unit 10 for transmit electrical signals.

In this implementation, the three surge protection units are all thermal protection varistor, as shown in FIGS. 15 and 16. Each thermal protection varistor has three external leading out terminals. The leading out terminal led out from the varistor is marked as J1, the leading out terminal led out from the common terminal between the varistor and the thermal fuse is marked as J2, and the leading out terminal led out from the thermal fuse is marked as J3.

Referring to FIG. 20, each surge protection unit may be electrically connected to plug-sleeve part 401 of each electrical connection unit. Specifically, leading out terminal J3 of first surge protection unit 3 a and leading out terminal J3 of third surge protection unit 3 c may be both inserted into plug-sleeve part 401 of second electrical connection unit 4 b so that an electrical connection is then formed by soldering or pressure welding. Leading out terminal J1 of first surge protection unit 3 a and leading out terminal J3 of second surge protection unit 3 b may be both inserted into plug-sleeve part 401 of first electrical connection unit 4 a so that an electrical connection is then formed by soldering or pressure welding. First surge protection unit 3 a, second surge protection unit 3 b and third surge protection unit 3 c are all connected to failure indication component 6. Leading out terminal J1 of second surge protection unit 3 b and leading out terminal J1 of third surge protection unit 3 c are respectively inserted into two hole-type terminals of connecting electrode 702 in gas discharge tube component 7 so that an electrical connection is then formed by soldering or pressure welding. The insulation layer is removed from ground connection wire and an end of ground connection wire is then inserted into the remaining hole-type terminal of connecting electrode 702 so that an electrical connection is then formed by soldering or pressure welding. Surge protection unit group 3 and electrical connection unit group 4 are both installed between shell 2 and base 5.

Sealing ring 9 may be provided between shell 2 and base 5 and base 5 is connected too shell 2 by tapping screw 8.

The Second Implementation

The second implementation is similar to the first implementation, and the differences are provided as below:

As shown in FIGS. 10, 12, 14, 21, first surge protection unit 3 a is formed by a first varistor, second surge protection unit 3 b is formed by a second varistor and a first thermal fuse connected in series, and third surge protection unit 3 c is formed by a third varistor and a second thermal fuse connected in series. Second electrical connection unit 4 b is also connected to a third thermal fuse in series.

As shown in FIG. 18, first electrical connection unit 4 a, third electrical connection unit 4 c are both composed of plug-sleeve part 401 and insulated conductive wire 402. As shown in FIG. 19, second electrical connection unit 4 b includes plug-in part 403, insulated conductive wire 402 and transition electrode 405 for connecting insulated conductive wire 402 to each surge protection unit. Division plate 404 for support and insulation function is provided between plug-in part 403 and transition electrode 405.

One end of leading out terminal J2 of first surge protection unit 3 a is inserted into plug-in part 403 of second electrical connection unit 4 b, so that an electrical connection is then formed by soldering or pressure welding. The other end of leading out terminal J2 is connected to failure indication component 6. Leading out terminal J3 of first surge protection unit 3 a and leading out terminal J3 of third surge protection unit 3 c may be both inserted into transition electrode 405 of second electrical connection unit 4 b, so that an electrical connection is then formed by soldering or pressure welding. The insulation layer is removed from insulated conductive wire 402 and an end of insulated conductive wire 402 is then inserted into transition electrode 405 from bottom to top and connected to transition electrode 405 by soldering or pressure welding.

For a skilled person in the art, it is easy to conceive of many modifications and other embodiments of the application. The contents of descriptions above and the associated drawings in the application have a useful technical motivation. Thus, the present application is not limited to specific embodiments disclosed here, but also includes various modifications and other embodiments within the scope of the claims. Although in the context, certain specific terms are used, they are only used for a general and descriptive sense, and do not constitute a limitation. 

What is claimed is:
 1. A photocontrol device comprising: a photocontrol unit for detecting ambient light condition; a surge protection unit; a device base; a first connecting means for connecting the photocontrol unit to the device base; a second connecting means for connecting the surge protection unit to the photocontrol unit and the device base; and a grounding means for connecting the surge protection unit to the device base; wherein the surge protection unit is located between the photocontrol unit and the device base, or in the photocontrol unit, or in the device base; the second connecting means comprises connecting the surge protection unit in parallel to a phase line terminal and a neutral line terminal of the photocontrol unit; the grounding means comprises a ground line terminal of the surge protection unit connected to a conductive part on the device base by at least a ground connector, and the conductive part of the base unit is connected to ground; and the ground connector includes a first lock member, a second lock member and an elastic member, wherein the first lock member is connected to the second lock member, and the second lock member is connected to an elastic member.
 2. The photocontrol device of claim 1 wherein the conductive part is disposed in the device base, and the elastic member contacts the conductive part.
 3. The photocontrol device of claim 1, wherein the conductive part is a screw.
 4. The photocontrol device of claim 1, wherein the surge protection unit is integrated into the photocontrol unit to form a whole, wherein the first and the second connecting means includes a plug and a socket corresponding to the plug, and the plug of the photocontrol unit is connected to the socket of the device base in a plug-in manner.
 5. The photocontrol device of claim 1, wherein the surge protection unit is connected to the photocontrol unit by a connector provided on the surge protection unit.
 6. The photocontrol device of claim 1, wherein the surge protection unit is provided with at least one protection component, each protection component includes at least one varistor and at least one thermal protection device connected in series with each other.
 7. The photocontrol device of claim 6, wherein a gas discharge tube is connected to the varistor in series.
 8. A photocontrol device having surge protecting function comprising: a photocontrol unit, a surge protection unit, and a device base; wherein the photocontrol unit includes a first plug, the device base includes a first socket corresponding to the first plug; the surge protection unit is located between the photocontrol unit and the device base, or in the photocontrol unit, or in the device base; the surge protection unit is connected between a phase line terminal and a neutral line terminal of the photocontrol unit; a ground line terminal of the surge protection unit is directly connected to ground by a ground line; the phase line terminal of the surge protection unit is connected to the ground line; the neutral line terminal of the surge protection unit is connected to the ground line; the surge protection unit includes a second plug, the device base includes a second socket corresponding to the second plug; the first plug of the photocontrol unit is connected to the first socket of the surge protection unit to form a whole body, and the second plug of the surge protection unit is connected to the second socket of the device base.
 9. The photocontrol device of claim 8, wherein the ground line terminal is attached to an outer surface of the surge protection unit.
 10. The photocontrol device of claim 9, wherein the surge protection unit is provided with at least one protection component, each protection component includes at least one varistor and at least one thermal protection device connected in series with each other.
 11. The photocontrol device with a surge protecting function according to claim 10, wherein a gas discharge tube is connected to the varistor in series. 